I see this on a daily basis and have seen in at multiple companies:
"Non-Senior" engineers who have to pretty much mentor "Senior" engineers; the "Senior" being given the title due to X years of experience instead of actual knowledge and knowhow and of course the reverse where the "Non-Senior" does not get promoted because he does not have the required ~years of experience~.
I see it more rarely amongst higher job titles though. It's more difficult for a senior engineer to make it to lead or principal when they do not have the skills.
The last time I had a job like this I left it. There was a sr. who consistently turned out sloppy work, scoffed at tests, and constantly caused production fires.
His boss loved him because he was always working hard after hours to correct his own sloppy mistakes.
I realized that I was probably more senior than my own boss and went and found a new job.
I used to wonder about this when I was younger. Now, older, I think the answer is that "senior" people are paid more, etc., because they can be trusted to generally tow the rope in the direction the company wants. They're usually not disruptive and usually do act professionally.
None of that has much to do with skill. As for skill, on average they're somewhat more skilled, but it's a smallish effect.
I do happen to be more technically skilled than most around me, but other skills matter more. I can avoid needlessly ruffling feathers. I can often foresee that a project will crash and burn months or years in advance. I can talk to people going through personal crises. This is all learned over long years.
Of course they do, they actually need senior knowledege.
I've seen a lot of people who were given senior titles without the accompanying knowledege, its really polluted the talent pool.
Finding "senior" engineers who write forkbombs is more common than you'd think.
Based on what I've seen across multiple companies, only the biggest and most experienced ones understood how to do leveling correctly. Everyone else was basically flying by the seat of their pants.
I think it's much more productive to label software engineers as being in stage 1 through stage 4 for most companies, and for 1000+ add stage 5 and for 10000+ add stage 6.
There was also a stretch of time following the dotcom bust when companies were handing out inflated titles rather than actual promotions or pay increases. I could be misremembering, but my memory is that was when titles became meaningless.
"Non-Senior" engineers who have to pretty much mentor "Senior" engineers; the "Senior" being given the title due to X years of experience instead of actual knowledge and knowhow and of course the reverse where the "Non-Senior" does not get promoted because he does not have the required ~years of experience~.
I see it more rarely amongst higher job titles though. It's more difficult for a senior engineer to make it to lead or principal when they do not have the skills.